Page 689 of 2493
SEF221W
Component InspectionNJEC1247HEATED OXYGEN SENSOR 2 HEATER (REAR)NJEC1247S01Check the following.
1. Check resistance between terminals 1 and 4.
Resistance: 2.3 - 4.3Wat 25ÉC (77ÉF)
2. Check continuity.
Terminal No. Continuity
1 and 2, 3, 4
No
4 and 1, 2, 3
If NG, replace the heated oxygen sensor 2 (rear).
CAUTION:
+Discard any heated oxygen sensor which has been
dropped from a height of more than 0.5 m (19.7 in) onto a
hard surface such as a concrete floor; use a new one.
+Before installing new oxygen sensor, clean exhaust sys-
tem threads using Oxygen Sensor Thread Cleaner tool
and approved anti-seize lubricant.
HEATED OXYGEN SENSOR 2 HEATER (REAR)QG
Component Inspection
EC-393
Page 690 of 2493

SEF058X
JEF835Z
Component DescriptionNJEC1741The crankshaft position sensor (POS) is located on the right-rear
wall of the cylinder block in relation to the signal plate at the rear
end of the crankshaft.
The sensor consists of a permanent magnet, and hall IC.
When the engine is running, the high and low parts of the teeth
cause the gap with the sensor to change.
The changing gap causes the magnetic field near the sensor to
change.
Due to the changing magnetic field, the voltage from the sensor
changes.
The ECM receives the voltage signal and detects the fluctuation of
the engine revolution.
ECM Terminals and Reference ValueNJEC1742Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (AC Voltage)
85 RCrankshaft position
sensor (POS)[Engine is running]
+Warm-up condition
+Idle speed3-4V
SEF979W
[Engine is running]
+Engine speed is 2,000 rpm3-4V
SEF980W
CRANKSHAFT POSITION SENSOR (POS)QG
Component Description
EC-394
Page 691 of 2493
Wiring DiagramNJEC1743
YEC990
CRANKSHAFT POSITION SENSOR (POS)QG
Wiring Diagram
EC-395
Page 692 of 2493
Diagnostic ProcedureNJEC1744
1 CHECK OVERALL FUNCTION
1. Start engine and let it idle.
2. Check voltage between ECM terminal 85 and ground.
SEF761Z
OK or NG
OK©INSPECTION END
NG©GO TO 2.
2 RETIGHTEN GROUND SCREWS
1. Turn ignition switch ªOFFº.
2. Loosen and retighten engine ground screws.
JEF104Y
©GO TO 3.
CRANKSHAFT POSITION SENSOR (POS)QG
Diagnostic Procedure
EC-396
Page 693 of 2493
3 CHECK POWER SUPPLY
1. Disconnect crankshaft position sensor harness connector.
JEF835Z
2. Turn ignition switch ªONº.
3. Check voltage between terminal 3 and ground with CONSULT-II or tester.
SEF113Y
OK or NG
OK©GO TO 5.
NG©GO TO 4.
4 DETECT MALFUNCTIONING PART
Check the following.
+Joint connector-6
+Harness for open or short between joint connector and ECM relay
+Harness for open or short between crankshaft position sensor and joint connector
+Harness for open or short between joint connector and ECM
+ECM relay
©Repair open circuit or short to ground or short to power in harness or connectors.
CRANKSHAFT POSITION SENSOR (POS)QG
Diagnostic Procedure (Cont'd)
EC-397
Page 694 of 2493

5 CHECK INPUT SIGNAL CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connectors.
JEF835Z
3. Check continuity between ECM terminal 85 and crankshaft position sensor harness connector terminal 2.
Refer to wiring diagram.
Continuity should exist.
4. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 6.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
6 CHECK GROUND CIRCUIT
1. Reconnect ECM harness connector.
2. Check harness continuity between terminal 1 and engine ground.
Refer to wiring diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 8.
NG©GO TO 7.
7 DETECT MALFUNCTIONING PART
Check the following.
+Harness for open between crankshaft position sensor harness connector terminal 1 and engine ground.
©Repair open circuit or short to power in harness or connectors.
8 CHECK CRANKSHAFT POSITION SENSOR
Refer to ªComponent Inspectionº, EC-399.
OK or NG
OK©GO TO 9.
NG©Replace crankshaft position sensor.
9 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-144.
©INSPECTION END
CRANKSHAFT POSITION SENSOR (POS)QG
Diagnostic Procedure (Cont'd)
EC-398
Page 695 of 2493
SEF121X
Component InspectionNJEC1745CRANKSHAFT POSITION SENSOR (POS)NJEC1745S011. Disconnect crankshaft position sensor (POS) harness connec-
tor.
2. Loosen the fixing bolt of the sensor.
3. Remove the sensor.
4. Visually check the sensor for chipping.
SEF122X
5. Check resistance as shown in the figure.
Terminal No. (Polarity) ResistanceW[at 25ÉC (77ÉF)]
3 (+) - 1 (±)
Except 0 or¥ 2 (+) - 1 (±)
3 (+) - 2 (±)
If NG, replace crankshaft position sensor.
CRANKSHAFT POSITION SENSOR (POS)QG
Component Inspection
EC-399
Page 696 of 2493

DescriptionNJEC1746SYSTEM DESCRIPTIONNJEC1746S01
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS) Engine speed
EGR vol-
ume controlEGR volume control valve Camshaft position sensor (PHASE) Engine speed and cylinder number
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Ignition switch Start signal
Throttle position sensor Throttle position
Vehicle speed sensor Vehicle speed
Battery Battery voltage
Air conditioner switch Air conditioner operation
Power steering oil pressure switch Power steering load signal
Electrical load Electrical load signal
PNP switch Park/Neutral position signal
This system controls flow rate of EGR led from exhaust manifold
to intake manifold. The opening of the EGR by-pass passage in the
EGR volume control valve changes to control the flow rate. A
built-in step motor moves the valve in steps corresponding to the
ECM output pulses. The opening of the valve varies for optimum
engine control. The optimum value stored in the ECM is determined
by considering various engine conditions. The EGR volume control
valve remains close under the following conditions.
+Low engine coolant temperature
+Engine starting
+High-speed engine operation
+Extremely light load engine operation
+Engine idling
+Excessively high engine coolant temperature
+Wide open throttle
+Mass air flow sensor malfunction
+Low battery voltage
SEF551W
EGR VOLUME CONTROL SYSTEM (WHERE FITTED)QG
Description
EC-400